The allegations are that the German telecoms giant carried out surveillance on its own managers and on journalists.

Dr. Gerhard Schäfer, former Presiding Judge at the Federal Court of Justice, will assist Deutsche Telekom AG as an expert in the investigations. Deutsche Telekom said that Dr. Schäfer will examine all relevant data security aspects of the allegations and draw up a new data security plan for the Group.

Deutsche Telekom said that the allegations are not of phone tapping, but of misuse of call records: details of the time, duration and participants of calls.

"I am shaken to the core by these allegations. We take the situation most seriously. We have called in the public prosecutor's office and will support them in their full investigation of these allegations," said René Obermann, Chairman of the Board of Management of Deutsche Telekom.